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Physics & Astronomy ETDs

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Articles 181 - 210 of 251

Full-Text Articles in Astrophysics and Astronomy

On The Velocity Of Sound In Cubic Crystals, Stuart Fleming Hayes Aug 1962

On The Velocity Of Sound In Cubic Crystals, Stuart Fleming Hayes

Physics & Astronomy ETDs

The object of this inquiry is to examine the relation between plane wave sound velocities in cubic crystals and the elastic constants of such crystals. Leading directly into this an extensive treatment of the classical theory of elasticity as it pertains to the cubic system. An application of the results will be made by detailing a means for obtaining the elastic constants of plastic single-crystals from measurements of velocity made on poly crystalline specimens.


The Time Required For Nuclear Fission, William Earn Stein Jun 1962

The Time Required For Nuclear Fission, William Earn Stein

Physics & Astronomy ETDs

The present work is concerned with the mean lifetime of compound nuclei formed in the fast-neutron-induced-fission process. A new method for the measurement of these lifetimes is proposed. The present method is based on the recoil of the compound nucleus following neutron capture and the secondary electrons emitted by fission fragments. Previous experimental and theoretical work concerning the secondary electron yields for fission fragments and other charged particles are reviewed. The importance of the higher energy electrons, the so-called delta rays, formed in the primary ionization process is considered. The subsequent secondary ionization produced by these delta rays provirles a …


The He3 + T Reactions., Darryl B. Smith Jun 1962

The He3 + T Reactions., Darryl B. Smith

Physics & Astronomy ETDs

The energy distribution of the alpha particles and of protons frim the He3+ t reactions have been measured for 1.9-Mev incident tritons at laboratory angles of 30° for alpha, and both 30° and 90° for protons. Absolute cross selections are obtained. The spectra are discussed in terms of a model which assumes that uncorrelated three-body breakup and several two-stage processes all contribute independently to the cross section. The calculations based on this model are in excellent agreement with the observed spectral shapes. The neutron-proton correlation corresponding to the unbound singlet state of the deuteron is observed. The binding energy of …


The Energy Spectrum Of Gamma Rays Produced In Interstellar Matter By The Primary Cosmic Rays, Duquesne A. Wolf Jun 1962

The Energy Spectrum Of Gamma Rays Produced In Interstellar Matter By The Primary Cosmic Rays, Duquesne A. Wolf

Physics & Astronomy ETDs

With the advent of the launching of space exploration in the last decade there has been parallel scientific effort to determine the nature of cosmic radiation found in space.

This theoretical study has the objective of determining the energy spectrum of gamma rays produced in interstellar matter by the primary cosmic rays.


Multiple Scattering Of High Energy Electrons In A Cerenkov Counter, John Rehnberg Jun 1962

Multiple Scattering Of High Energy Electrons In A Cerenkov Counter, John Rehnberg

Physics & Astronomy ETDs

The purpose of this thesis is to present a procedure for calculating the fraction of high energy electrons incident on a Cerenkov counter which are scattered out of the region of detection.

With the assistance of Professor Christopher P. Leavitt of the University of New Mexico, a method of solving the above problem has been established. The method uses the theory of multiple scattering as described by Rossi and Greisen and a numerical integration technique to evaluate the effective or average scattering distribution function for the Cerenkov counter. A relationship is developed which can be programmed on a Bendix G-15 …


Calibration Of A Liquid Scintillator With Geiger-Mueller Counters, William F. Hartman Jun 1962

Calibration Of A Liquid Scintillator With Geiger-Mueller Counters, William F. Hartman

Physics & Astronomy ETDs

It was the purpose of this experiment to examine the difference in the density determinations and, since the Geiger tube threshold is much lower, to calibrate the liquid scintillator so that it is capable to determining the absolute particle density with greater accuracy.


A Telemetric Compass, Paul Nelson Jr. May 1962

A Telemetric Compass, Paul Nelson Jr.

Physics & Astronomy ETDs

In certain types of experiments involving balloon-borne equipment it is desirable to know how the orientation of the apparatus varies with time. The author has investigated a method of telemetering azimuthal orientation from a balloon to the ground, and has constructed a protoype of a telemetering magnetic compass. The basis of the compass is a rotating-ring magnetometer of the type first described by Nielsen (1) and used by others (2,3,4) for various purposes. The output of this device consists of two a.c. signals, whose relative phase is determined by the orientation of the magnetometer with respect to the external magnetic …


Anisotropy Of The Cosmic-Ray Flux Caused By An Interplanetary Magnetic Field, Ronald R. Harrington May 1962

Anisotropy Of The Cosmic-Ray Flux Caused By An Interplanetary Magnetic Field, Ronald R. Harrington

Physics & Astronomy ETDs

The purpose of this study is to investigate the possibility that this diurnal variation in cosmic-ray flux may be due to a general dipole-like magnetic field centered upon the sun.


A Study Of The Elastic Scattering Of 25-Mev He3 Ions From Various Nuclei, Dale D. Armstrong May 1962

A Study Of The Elastic Scattering Of 25-Mev He3 Ions From Various Nuclei, Dale D. Armstrong

Physics & Astronomy ETDs

The validity of the assumption of strong absorption as the basis for the description of the interaction of He3 ions and nuclei was not definitely established and probably cannot be established without the application of more sophisticated theories.


Origins Of Shock-Induced Luminescence In Quartz, William P. Brooks May 1962

Origins Of Shock-Induced Luminescence In Quartz, William P. Brooks

Physics & Astronomy ETDs

Alpha quartz is a piezoelectric material. As such, it will yield voltage under stress. When shocked with high explosive systems, the material is also luminescent. This luminescence is quite intense and can be recorded on normal films at submicrosecond exposure times.

The luminescence appears in various patterns determined both by the explosive system used and by the orientation of the quartz.

Fused quartz exhibits luminescence to a lesser degree. Since fused quartz is not piezoelectric, it is helpful in the determination of the origin of the luminescence in crystalline alpha quartz.

This study of the origin of the luminescence in …


A Liquid Hydrogen Bubble Chamber Designed For Use As A Neutron Spectrometer, Edward R. Flynn May 1962

A Liquid Hydrogen Bubble Chamber Designed For Use As A Neutron Spectrometer, Edward R. Flynn

Physics & Astronomy ETDs

A liquid hydrogen bubble chamber for use as a neutron spectrometer has been constructed and operated. The chamber employs 90o stereography and is expanded by a piston located in the liquid. The construction and operation of the chamber are described. A special measuring microscope for analyzing the data is described along with the associated electronics for digitizing the screws of this device. Reading rates of 60 proton recoils per hour have been obtained and the reading procedure is discussed. Preliminary results from a neutron-proton differential cross section measurement indicates a resolution of 5% may be obtained with 22 Mev …


A Satellite Ratemeter Circuit, Daniel P. Christman Mar 1962

A Satellite Ratemeter Circuit, Daniel P. Christman

Physics & Astronomy ETDs

It was proposed that an attempt be made to measure the directional energy of high-energy primary gamma radiations in space. The difficulties of such an effort are readily obvious. To escape the environmental air envelope of the earth and to lessen the interference of secondary radiations, an instrument package would have to placed into a known orbital trajectory.


A Telemetering Inclinometer, Robert G. Geil Mar 1962

A Telemetering Inclinometer, Robert G. Geil

Physics & Astronomy ETDs

In present day experiments in Atmospheric Physics, information from the experiment is sometimes telemetered to observers located at positions remote from the apparatus. To obtain data from the stratosphere an instrument package may be sent aloft suspended from balloons. It is often desirable to know the azimuthal orientation of the instrument package.

To achieve this purpose a rotating ring magnetometer has been developed at the University of New Mexico to measure azimuthal orientation using the earth's magnetic field for a reference. This is sufficient for many purposes. However, due to the wind currents the package suspended beneath the balloon may …


"Invariant Imbedding" And Wave Propagation In Inhomogeneous Media, Crawford J. Maccallum Dec 1961

"Invariant Imbedding" And Wave Propagation In Inhomogeneous Media, Crawford J. Maccallum

Physics & Astronomy ETDs

We wish now to address ourselves to that problem which can be described in physical terms as the reflection and transmission of "waves" by and through some sort of "transition region" between two homogeneous media. At this stage we will work strictly within one dimension; later on this severe restriction will be somewhat eased. For simplicity of notation we will for the present give the transition region a finite thickness h; later on we will often allow h to become infinite when the disturbance due to the transition region dies away fast enough with distance.


Long-Range Particles From Nuclear Fission, Ralph A. Nobles Oct 1961

Long-Range Particles From Nuclear Fission, Ralph A. Nobles

Physics & Astronomy ETDs

This work is concerned with experimental observations of the long-range particles which are occasionally emitted by fissioning nuclei. These particles are known to be principally alpha particles and are of interest because they are associated with the configuration of the nucleus at the crucial time of scission. Observations were made of the energy spectra of long-range particles by means of a thallium-activated multiple CsI crystal scintillator device.


A Calibration Method For Satellite Cerenkov Instrumentals, Robert E. Dekinder Jr. Jun 1961

A Calibration Method For Satellite Cerenkov Instrumentals, Robert E. Dekinder Jr.

Physics & Astronomy ETDs

The problem posed for this thesis is one of determining a method of calibrating a photomultiplier tube when it is contained in an orbiting instrumentation package. Since it is planned for the satellite to remain in orbit for about two years, a method to determine drift of the telemetered output versus the selected radiation input would be very desirable. This drift could arise from changes in the power supplied to the system, or by the telemetering or logic circuits changing characteristics from exposure to cosmic radiation. The situation requires that light of constant intensity be produced in the "field of …


The Wavelength Shifting Of Cerenkov Radiation, Philip A. Deutchman May 1961

The Wavelength Shifting Of Cerenkov Radiation, Philip A. Deutchman

Physics & Astronomy ETDs

The main interest in this paper is to study the effect of the florescent wavelength shifter "POPOP" with respect to Cerenkov radiation and to determine how the efficiency of a Cerenkov counter is affected.


Angular Distribution Of Electrons In Extensive Air Showers, Don D. Laniewski May 1961

Angular Distribution Of Electrons In Extensive Air Showers, Don D. Laniewski

Physics & Astronomy ETDs

Electrons are the main products of an extensive air shower and comprise approximately 90% of the shower. Since these electrons are the most numerous particles near the axis of a large shower and are not easily detected, extensive air showers are most easily studied by means of the electronic component. Thus, whatever concern there may be about the nucleonic cascade of which the electron is an outgrowth, it is necessary first to understand the development of the electronic component and is lateral and angular distribution. Also, for the correct analysis of any experimental data, it is of particular importance to …


An Analysis Of Bursting Bubbles At Liquid Surfaces, Keith James Gilbert May 1961

An Analysis Of Bursting Bubbles At Liquid Surfaces, Keith James Gilbert

Physics & Astronomy ETDs

This phenomenon of the spray produced by bursting bubbles at liquid surfaces is certainly familiar to drinkers of carbonated soda pop, champagne and other effervescent liquids. This same phenomenon has been observed at ocean surfaces. Small bubbles, some of which originate at great depths, rise to the surface and break; tiny droplet is thrown upward from most of the imploding bubbles. Some of these droplets may be caught and carried into the atmosphere by winds sweeping along the surface. The droplets evaporate but leave small particles of salt suspended in the air; the particles then serve as condensation nuclei and …


Design Of An Instrument To Detect High Energy Photons At High Altitudes, Donald L. Evans May 1961

Design Of An Instrument To Detect High Energy Photons At High Altitudes, Donald L. Evans

Physics & Astronomy ETDs

The purpose of this thesis is to design a high altitude instrument which will detect photons with an energy greater than 1 Bev, and which will discriminate between zenith and albedo radiation.


Absorbance Of The Oh Radical In A Specific Wavelength Interval Near 309a, Paul F. Bird May 1961

Absorbance Of The Oh Radical In A Specific Wavelength Interval Near 309a, Paul F. Bird

Physics & Astronomy ETDs

The absorbance of the OH radical as a function of optical density was studied by computing the absorbance for an incident radiation in the wavelength interval 3089A-3097A. The absorbance was studied for 3 different temperatures and various values of the parameters specifying the line shapes and magnitude of the spectral absorption coefficient.


Isomerism In Bromine Nuclei, Albert Goodman Feb 1961

Isomerism In Bromine Nuclei, Albert Goodman

Physics & Astronomy ETDs

If the phenomenon of isomerism occurred in bromine nuclei, it would be of great help in elaborating the level schemes of these isotopes. The occurrence of isomerism in the odd isotopes of arsenic and rubidium, the nearest odd-Z neighbors to bromine, suggested similar behavior in bromine odd-Z isotopes. In this investigation, the pulsed-beam method was used to search for isomers. The procedure consisted of pulsing the beam of a Van de Graaff accelerator and counting any resulting activities during the time between beam pulses. After preliminary surveys during which natural bromine was bombarded with neutrons and natural selenium was bombarded …


A Proposal For The Use Of The Method Of Characteristics As A Condition On The Numerical Solutions Of Two-Dimensional Lagrangian Isentropic Flow, Christian D. Anderson Jan 1961

A Proposal For The Use Of The Method Of Characteristics As A Condition On The Numerical Solutions Of Two-Dimensional Lagrangian Isentropic Flow, Christian D. Anderson

Physics & Astronomy ETDs

The method of characteristics has been widely used in two- dimensional problems (i.e., one spatial dimension and time or two spatial dimensions for the steady state), and it was felt that this method, in all or part, could be applied to time-dependent, two- space hydrodynamics.

In this paper we have done the following:

1. Derived the two-dimensional, time-dependent, nonviscous Lagrangian Equations;

2. Discussed, in general, some aspects of the method of characteristics;

3. Applied the method to our Lagrangian equations; and finally,

4. Proposed a possible application of our results to the numerical solution of the Lagrangian equations.

In …


Muon Component Of Extensive Air Showers., Ryan Pierson Jr. Sep 1960

Muon Component Of Extensive Air Showers., Ryan Pierson Jr.

Physics & Astronomy ETDs

The purpose of this thesis is to determine how the muon component of an extensive air shower varies with the energy of the incident primary particle and different values of inelasticity and multiplicity for the nuclear interactions according to a simple theory of extensive air showers suggested by Professor Roy Thomas of the University of New Mexico. The method of attacking this problem will be to calculate the number of muons resulting from decay of pions produced in each nuclear interaction of the primary particle and from this the total number of muons passing through certain levels of the earth’s …


Measurements Of The Intensity Of Mu-Mesons In Cosmic Rays During A Period Of Unusual Solar Activity, Ronald A. Korsak Jun 1960

Measurements Of The Intensity Of Mu-Mesons In Cosmic Rays During A Period Of Unusual Solar Activity, Ronald A. Korsak

Physics & Astronomy ETDs

Because of the incomplete understanding of the processes which cosmic rays undergo in the atmosphere, there is still no generally accepted treatment of the atmospheric dependent variations of the intensity or preferred method of establishing correct coefficients.


Time Variations On The Cosmic-Ray Flux Near The Geomagnetic Equator, Charles L. Hyder Jun 1960

Time Variations On The Cosmic-Ray Flux Near The Geomagnetic Equator, Charles L. Hyder

Physics & Astronomy ETDs

The search for an anisotrophy in the penetrating component of the cosmic-ray flux is usually carried out with narrow-angle directionally sensitive detectors located near the surface of the earth. Directional sensitivity is achieved by using a cosmic-ray telescope, consisting of Geiger counters or of scintillation counters, in a coincidence arrangement. Thus a solid angle of acceptance for the cosmic-ray particles is defined.


Three-Color Photometry Of The Zodiacal Light, Alan W. Peterson Jun 1960

Three-Color Photometry Of The Zodiacal Light, Alan W. Peterson

Physics & Astronomy ETDs

The major effort of the observational phase of this investigation was placed upon obtaining absolute intensity maps of the zodiacal light in three different colors. Emphasis was also placed upon measurements of polarization and upon photographing the spectrum of the zodiacal light.


Core Location Of Extensive Air Showers, James H. Jett May 1960

Core Location Of Extensive Air Showers, James H. Jett

Physics & Astronomy ETDs

Extensive air showers have been studied as part of cosmic ray phenomenology since 1938. They are made up of electrons, photons, and many other particles which traverse the earth's atmosphere toward the earth. The showers are initiated by high energy cosmic rays. The primary cosmic rays are nuclei which have been stripped of their orbital electrons.

To this end an experiment is underway in the University of New Mexico Physics Department to determine the amount of energy transferred from the core of the shower to the electron-photon cascade. By using a detector telescope with appropriate absorber between the two detectors, …


A Numerical Solution For Weak Disturbances In A Large Scale Hydromagnetic Field, Patrick J. Blewett Jun 1959

A Numerical Solution For Weak Disturbances In A Large Scale Hydromagnetic Field, Patrick J. Blewett

Physics & Astronomy ETDs

Our concern here will be to investigate the form of certain solutions of equation (7); we will be content with a two-dimensional analysis.


Method For Interpreting Extensive Air Shower Data, Darrell C. Kent Jun 1959

Method For Interpreting Extensive Air Shower Data, Darrell C. Kent

Physics & Astronomy ETDs

Three major topics are discussed in this thesis. The first of these has immediate application to analysis of air shower data which is presently being gathered by two large scintillation tanks located immediately behind the University of New Mexico physics building. The data with which the other two topics are concerned cannot be gathered with present equipment, but these preliminary calculations have been performed in anticipation of the installation of the appropriate apparatus.